The present invention relates to a semiconductor device, for example, relates to an effective technique to be applied to a semiconductor device using nitride semiconductor layers.
Japanese Patent No. 3960957 (Patent Document 1) describes a technique for forming a buffer layer from a laminated structure of a first layer formed of a GaN layer that is a nitride semiconductor layer and a second layer formed of an AlGaN layer that is a nitride semiconductor layer and having a band larger than that of the first layer. In this technique, magnesium (Mg) that is an acceptor is introduced into both the first layer and the second layer and the addition amount of the magnesium introduced into the first layer and the addition amount of the magnesium introduced into the second layer are the same.